In the manufacture of plastic containers and packages utilizing such plastic containers, it has become desirable in one form of package to have internal threads on the inner surface of the finish for engaging external threads on a closure in the shape of a measuring cup. Such internal threads are difficult to form and control accurately to produce a proper seal.
Accordingly, among the objectives of the present invention are to provide a plastic container having internal threads which can be manufactured at lower cost and more easily, which will provide the desired dimensional control of the threads, and which can be adapted to use a closure that cooperates with the finish to provide a proper seal, and which can also be adapted to the utilization of a circumferentially oriented pour spout.
In accordance with the invention, the plastic container comprises a plastic blow molded container having an annular finish, an insert positioned in the finish and interengaged with the internal surface of the finish. The insert has internal threads for receiving a closure such as an enlarged closure in the form of a self-draining measuring cup having external threads on the lower end thereof and a peripheral flange sealingly engaging the free end of the finish.